I’m guessing the possibility of relationships with npcs has already been asked, i’ve not played with npcs yet so I don’t know how dep it goes.
I was thinking if it would be possible for your partner to react if you suddenly mutated, three extra arms for example?
You both wake up one morning, you with your new arms, your partner tells you “I aint into that” and runs off into the new days sawn.
Or some npcs are only attracted to certain mutations…
I dunno what that would add to the game. Just something I randomly thought of